Chicken–Lemon Balm Broth

• 500 ml (17 fl oz/2 cups) light white chicken stock

Heat the stock to 70°C (158°F). Add the kelp and lemon balm and infuse for 15 minutes. Pass the stock through a sieve lined with muslin (cheesecloth) into a clean saucepan, add the soy sauce and vinegar and check the seasoning. Take a ladle of the seasone